A pipe fitting is a fitting used to connect pipe segments, that is placed at a junction or transition in a piping system and may be used to change flow characteristics such as direction and flow rate. In this instance valves are not classified a pipe fittings, they are classified as valves.
A pipe T junction is a pipe fitting with three ports, one of which is perpendicularly aligned to the other two (T formation), used to redistribute flow among the ports and/or to change the direction of flow between connected elements.